SUMMARY OF WORK A. To determine whether ischemic ST segment changes occurring only during recovery from maximal treadmill exercise predict future coronary events (CE) in clinically healthy populations, we compared 2 groups of BLSA subjects: 150 with 1mm ST segment depression occurring during exercise (Group 1) and 64 with such ST changes limited only to recovery (Group 2). The 2 groups were similar in age, gender, and coronary risk factors.Over a mean follow-up of 7.3 years, CE (angina pectoris, myocardial infarction or coronary death) developed in 14.6% of Group 1 and 18.7% of Group 2, p=NS.By logistic regression analyses older age (p=.0007), higher serum cholesterol (p=.002) and shorter exercise duration (p=.002) but not the time of ST depression onset(exercise vs recovery) were independent predictors of future CE. B. To determine whether non-diagnostic ST segment responses to treadmill exercise confer increased risk for future coronary events (CE) compared with completely negative ST responses, we examined the incidence of coronary events in 1083 BLSA subjects clinically free from coronary heart disease. Over a mean follow-up of 8.7 years, coronary events developed in 76 subjects. Subjects with non-diagnostic ST segment responses 18:2, 18:4, and 18:5 by Minnesota Code had odds ratios for CE of 0.94, 1.65, and 2.14, all p=NS compared with those with negative ST segment responses. C. We evaluated whether a positive relationship exists between increased intimal- medical thickness (IMT) of the common carotid artery (CCA) and subclinical coronary artery disease (CAD) similar to that documented for symptomatic CAD. In 290 BLSA volunteers, IMT was positively associated with age (r=0.63), CCA diameter (r=0.30) and systolic blood pressure (r=0.27), each p<.0001. By multiple regression analysis, IMT was best explained by age (p<0.0001), CCA diameter (p<0.001), possible CAD (p<0.01) and manifest CAD (p<0.0001).